Interest in Whitney Houston's swan song should all but ensure decent business for this hopelessly scattered remake.

As a remake of a cult ’70s musical developed as a star vehicle for a former “American Idol” winner, “Sparkle” would seem to have all the makings of a low-rent “Dreamgirls,” perfectly serviceable if sometimes hopelessly scattered. Or at least it would have been that vehicle, were it not saddled with the unfortunate significance of featuring Whitney Houston’s final performance, having wrapped mere months before her sudden death in February. A film with foundations this slight can’t help but crumble under such a burden, although it’s precisely the interest in Houston’s swan song that should all but ensure decent business.

The 1976 original, which featured music from Curtis Mayfield and a script by a young Joel Schumacher, focused on a trio of sibling singers in 1950s Harlem, stitching together a zany patchwork of great music, overheated melodrama and risible social commentary. Director Salim Akil’s remake tones down its predecessor’s incipient weirdness, and relocates the action to late-’60s Detroit, where mousy young church singer Sparkle (Jordin Sparks) is eager to break into the soul scene exploding all around her.

An “Idol” alum whose career has been idling for the past few years, Sparks should see a healthy Q-rating bump from her first starring role here; she’s cute as a button and can belt with the best of ‘em, even if her range of expression is mostly limited to the extremes of either ecstatic well-being or lip-quivering sadness. She’s certainly likable enough, and it’s not her fault that she frequently disappears from view in her own movie.

Sparks is tasked with playing the wallflower in a family full of forceful personalities, which does the inexperienced thesp no favors. Her wild-child older sister, Sister (Carmen Ejogo), is a sort of Motor City Ishtar, a tsunami of melisma, swiveling hips, sex, drugs and violence. Her other sister, Dolores (Tika Sumpter), is a proto-Black Power firebrand who takes on potential record-industry grifters like a ’60s Wendy Day. And Houston plays the family’s iron-fisted, churchgoing matriarch, Emma, whose own rough experiences with the music business and men cause her to deny both to her progeny.

What Sparkle does have is a knack for songwriting. Surreptitiously penning songs for Sister to perform at sweaty clubs, Sparkle catches the eye of fellow church member Stix (Derek Luke), whose romantic intentions dovetail conveniently with his dreams of becoming the next Berry Gordy. Assembling the sisters into a Supremes-style trio, Stix somehow navigates them to a spot opening for Aretha Franklin before their mother has even begun to wonder where they’ve been every night. Meanwhile, Sister has traded the affections of a sweet local boy (Omari Hardwick) for conk-haired, diamond-flashing local celebrity Satin (Mike Epps), a slithering viper who sets about destroying all familial harmony.

“Sparkle” deals in such well-worn rise-and-fall music-bio tropes that it’s hard to blame it for simply coasting on narrative shorthand at times. But the lackadaisical storytelling can inch toward outright laziness, with a number of key plot points elided from view while whole scenes are wasted on foreshadowing character developments that never actually develop.

Of course, all eyes are bound to be on Houston here, and her performance registers as a success in its mere normalcy: She looks her age and no more, delivers her lines crisply and has adequate chemistry with her co-stars. Aside from one gasp-inducing line — “Is my life not enough of a cautionary tale for you?” — ghoulish gossipmongers eager to scour the screen for hints of her own personal troubles will thankfully leave the theater empty-handed.

For her one onscreen number, Houston performs the century-old gospel standard “His Eye Is on the Sparrow,” and it’s a bit of an odd one. Backed by a seasick piano and a choir arrangement that never quite taps into the rhythm of the song, Houston sounds a tad hoarse and uncharacteristically sticks to the lower end of her range. But given the funereal mood of the scene in which the song appears, it can’t help but be affecting.

Ejogo seems to be channeling Beyonce’s interpretation of Diana Ross more than the genuine article, though she puts in a solid shift all the same, as does the ever-reliable Luke. The best performance comes from comedian Epps: Evoking a strange crossbreed of Morris Day and Patrick Bateman, his Satin manages to be genuinely chilling in his dead-eyed sociopathology while still earning the film’s biggest laughs.

R. Kelly serves as executive music consultant here, producing tasteful covers of several Mayfield tunes, and penning a few new ones himself. Much like his own retro projects “Love Letter” and “Write Me Back,” Kelly’s contributions mingle the compositional framework of ’60s R&B with the quiet-storm smoothness of the 1980s, producing some climactic numbers that sound right, yet feel inescapably off.

Akim directs with professional flair during the music sequences, journeyman adequacy during the domestic scenes and amateur shoddiness during his few overreaching attempts at auteurial flourishes. Editing is a bit ragged, though most other tech specs are pro.